Rotary slurry pump



Feb. 4, 1964 v G. NEIDL 3,120,353

ROTARY SLURRY PUMP Filed Oct. 11, 1960 2 Sheets-Sheet 1 GE 0R6 NEIDL INVENTOR.

Feb. 4, 1964 Filed Oct. 11, 1960 G. NEIDL 3,120,353

ROTARY SLURRY PUMP 2 Sheets-Sheet 2 GEOEG NE IDL INVENTOR.

United States Patent 3,120,353 REITARY SLURRY PUMP Georg Neidl, Schoeiiiesserstrasse 103, Berlin- Frohnau, Germany Filed Get. 11, 1960, Ser. No. 61,934 4 Claims. (Cl. 241-46) This invention relates to a rotary pump, in particular one destined to the treatment and disposal of sewage, thick slurries and like liquids. It constitutes a continuation-in-part of the copending application Serial No. 637,230, filed on January 30, 1957, now Patent No. 2,956,503.

Specially designed centrifugal pumps have been used in pumping Waste water, thick slurries, plastic masses, concrete, mortar, sludge, mud, moor, sand, chemical pastes and other suspensions. It was shown, however, that these pumps clog easily, for the reason that tough or compact masses contained in the pumped matter, such as paper, rags, stones and the like, get easily stuck not only in the ducts of the centrifugal pump, but also at the point of contact between the rotary and the stationary portions of the pumps, where they jam.

According to the invention, these shortcomings are obviated by installing within a stationary cylindrical or somewhat spiral housing, on a drive shaft mounted concentrically to the axis of the housnig, a preferably diskshaped pump element of circular axial projection, attached obliquely to the shaft in such a Way that the said pump element, rotating inside the housing, sweeps a cylinder of revolution with a wobble motion caused by rotation. Provision is made for an axial inlet opening confronting the fiat surface of the inclined impeller and for one or more outlet openings at or near the periphery of the housing.

The pump element may be shaped as an elliptical disk, mounted at the inner end of the shaft with overhung supports, whereby the axial projection of said disk is circular and the outer boundary of same is uniformly spaced away from the inner cylindrical wall of the housing. This spacing or clearance is selected in relation to the size of the impurities contained in the pumped matter and must be large enough to prevent solid matter contained in the liquid from jamming between the walls of the housing and the pump element. In pumping Waste and other fluids containing large pieces of suspended matter such as beets, shells, fish and the like, this spacing is advantageous in that the exposed outer edge of the pump element acts as a cutting and grinding tool which cuts up, shreds and tears paper, rags and other solid components due to the high-speed rotation of the pump element. The inside walls of the housing in conjunction with the edges of the discharge nozzle act as holders with relation to the edges of the pump element in grinding, shredding and cutting. The pump is thereby suitable not only to pumping waste water, but also as a shredding machine. In contrast to the ordinary pumps equipped with wobble disks, the pumping action of the pump element is largely due to centrifugal action.

In order to augment the desired tearing and cutting action at the perimeter of the pump element, this element and, more specifically, those portions of its which adjoin the housing, may be appropriately provided with cutters or hooks, in particular saw teeth or blades.

As a means of providing positive protection against fabric rags contained in waste water enwrapping parts of the pump and the pump shaft in particular, care must be taken that no exposed shaft portions project inside the housing. This can be achieved by appropriately outfitting all of the pump impeller with hooks or teeth, and by mounting toothed disks onto the pump shaft, to the extent that same projects inside the housing, for the purpose of preventing rags from enveloping parts of the pump and tearing such rags with the aid of hooks and teeth.

Further details of the invention are illustrated with reference to the accompanying drawing in which:

FIG. 1 is a perspective view of a pump of the type claimed in my US. Patents Nos. 2,956,503 and 3,005,597 and incorporating the present improvement;

FIG. 2 is a side-elevational view thereof with parts broken away;

FIG. 3 is an axial cross-sectional view of the pump of FIGS. 1 and 2 with oblique impeller disk and a cylindrical body along the shaft between the disk and the housing;

FIG. 4 is an axial cross-sectional view of the pump rotor in which not only the shaft, but the outer boundary of the pump element bears saw-blade-like disks;

FIG. 5 is a cross-sectional View of a pump with a conical inside-cover attachment and shredder teeth on a diskshaped pump element; and

FIG. 6 is an elevational view of this conical attachment on the cover of the pump housing according to FIG. 5.

According to the pump illustrated in FIGS. 1 and 2, a shaft 3 mounted on two bearings 4, 5 is suspended from cover 1 of a cylindrical pump housing 2. Mounted at the inner end of said shaft 3 is an oblique disk-like pump impeller 6, which performs wobble movements as the shaft 3 rotates. The elliptical shape of the pump disk 6 is such that it is of circular axial projection, so that when this disk turns inside the housing 2, there is at every point the same clearance 7 between the edge of the disk and the inner cylindrical wall of the housing. It is also feasible to provide a circular disk which will appear elliptical in the direction of the axial projection which affords the alternative that the clearance between the circumference of the disk and the housing need not be uniform throughout.

On the shaft-bearing side, opposite the front end, the housing is sealed with a cover 8, provided with a central suction inlet 9. Provision is made for an outlet 10 at the cylindrical circumference of the housing.

Inasmuch as it may occur, in spite of the simple shape of the pump impeller, that impurities (e.g. fabrics and other textiles) wrap about the rod and are not centrifuged outwardly in spite of the centrifugal force, it may prove appropriate to provide the pump element at its circumference with teeth 38.

According to the embodiment shown in FIG. 3, a body with radical projections, such as a special saw blade or knife 154, is mounted on shaft 3 next to the main pump element 153, intermediate the impeller and the rear Wall of the housing at the spot where fabrics are particularly apt to wrap about the shaft. Optionally, the pump element 153 itself may be provided with external saw blades 155, 156, whereby these blades may be mounted perpendicularly or obliquely to the shaft or to each other. Whereas the saw blades 155 fully circle the pump element, the saw blade 156 circles only a portion of the rotor.

In the pump shown in FIG. 4, a spacer 161 is mounted between the rotating pump shaft 3 and the disk-shaped pump element 160, its front end having the shape of an obliquely cut cylinder and its surface being provided with several rows of pegs 161' projecting outwardly and designed to tear the rags and prevent their jamming and clogging the pump. The end of the spacer adjacent the shaft cover 162 clears a recess 163 in the cover 162, to avoid jamming of fabrics.

Inasmuch as the obliquely cut cylinder does not present a full circular outline when viewed perpendicularly to the pump shaft, textile fibers or the like obviously cannot become entangled thereon. Moreover, the disk-shaped pump element overlies to a degree the obliquely cut cylinder at its outer boundary inside the pump housing. Inasmuch as the disk-shaped pump element is provided with saw teeth or pegs, or is built as a cutter along its entire circumference, the obliquely cut cylinder is further protected against clogging.

In order to obviate the danger of tough fabrics, such as synthetic fibers, becoming enmeshed, the pump housing of FIG. 5 is provided with a a conical body 178 on the shaft side of the cover, whose direetrices are parallel to the pump disk 175. In terms of a radius, the disk-shaped pump element describes a conical surface in its rotation. Thus, between the radius of the pump disk and the cone, a very narrow radial gap is created. In this connection, the radius of the pump disk should be visualized as lying on the inclined plane of such disk. The surface of the rotor disk facing the cone bears, on the above-mentioned impeller radius, a number of axially offset teeth 177, cutters, barbs or blades. Similar projections 189, barbs, knives or points are co-operatingly provided on the conical segment.

The axially ofiset projections may be differently arranged along the rotor and the conical segment, for example in radial rows which, in the case of the cone, may also run in the shape of a cross (FIG. 6). Appropriately, the teeth and similar projections may be so positioned on the two elements that the teeth on one mesh with the tooth gaps on the other. Inasmuch as upon rotation the diskshaped rotor always lies parallel to the directrix of the conical body and that these opposite parallel positions rotate in the housing at the speed of the rotor, such fabrics as may enter the clearance between the rear wall and the impeller are safely torn to shreds and centrifuged from the housing, thus preventing possible clogging of the pump. In FIG. 5, the front end of disk 175 is not exposed to this danger, for the reason that it provides unimpeded passage from the inlet.

What I claim is:

'1. A pump for displacing liquids, comprising a housing forming a generally circularly cylindrical pump chamber provided with a substantially axial inlet and a substantially radial outlet for a liquid to be pumped as Well as a rear wall transverse to the axis of said chamber; a drive shaft extending axially into said housing remote from said inlet through said rear wall and rotatably journaled in said housing; a generally elliptical fiat impeller disk secured to said shaft within said chamber and inclined to the axis thereof while being spaced from an inner cylindrical wall of said chamber, whereby the periphery of said disk generates a generally circularly cylindrical surface substantially parallel to said inner wall upon rotation of said shaft, said inner wall substantially completely encircling said shaft, said impeller defining with said rear wall a peripheral clearance surrounding said shaft; and an annular body coaxial with said shaft within said clearance, said body being provided with a plurality of axially staggered members spaced from said disk and projecting generally radially into said chamber and co-operating with said disk for shredding solid matter suspended in said liquid within said clearance.

2. A pump for displacing liquids, comprising a housing forming a generally circularly cylindrical pump chamber provided with a substantially axial inlet and a substantially radial outlet for a liquid to be pumped as well as a rear wall transverse to the axis of said chamber; a drive shaft extending axially into said housing remote from said inlet through said rear wall and rotatably journaled in said housing; a generally elliptical fiat impeller disk, having a serrated periphery, secured to said shaft within said chamber and inclined to the axis thereof while being spaced from an inner cylindrical wall of said chamber, whereby the periphery of said disk generates a generally circularly cylindrical surface substantially parallel to said inner wall upon rotation of said shaft, said inner wall substantially completely encircling said surface, said impeller defining with said rear wall a peripheral clearance surrounding said shaft; and an annular body coaxial with said 4 shaft within said clearance, said body being provided With a plurality of axially staggered members spaced from said disk and projecting generally radially into said chamber, said body being secured to said shaft for shredding solid 5 matter suspended in said liquid within said clearance.

3. A pump for displacing liquids, comprising a housing forming a generally circularly cylindrical pump chamber provided with a substantially axial inlet and a substantially radial outlet for a liquid to be pumped as well as a 10 rear wall transverse to the axis of said chamber; a drive shaft extending axially into said housing remote from said inlet through said rear wall and rotatably journaled in said housing; a generally elliptical flat impeller disk secured to said shaft within said chamber and inclined to the axis thereof while being spaced from an inner cylindrical wall of said chamber, whereby the periphery of said disk generates a generally circularly cylindrical surface substantially parallel to said inner wall upon rotation of said shaft, said inner wall substantially completely encircling said surface, said impeller defining with said rear wall a peripheral clearance surrounding said shaft; a conical body rigid with said housing extending from said rear wall into said clearance coaxial with said shaft, said body conforming to a surface of revolution having a generatrix parallel to said impeller disk and being provided with a plurality of axially staggered members spaced from said disk and projecting generally radially outwardly into said chamber; and a plurality of axially staggered other members secured to said disk and projecting generally radially toward said body for co-operation with the spaced members thereof to shred solid matter in said clearance upon rotation of said shaft.

4. A pump for displacing liquids, comprising a housing forming a generally circularly cylindrical pump chamber provided with a substantially axial inlet and a substantially radial outlet for a liquid to be pumped as well as a rear wall transverse to the axis of said chamber; a drive shaft extending axially into said housing remote from said inlet through said rear wall and rotatably journaled in said housing; a generally elliptical flat impeller disk, having a serrated periphery secured to said shaft within said chamber and inclined to the axis thereof while being spaced from an inner cylindrical wall of said chamber, whereby the periphery of said disk generates a generally circularly cylindrical surface substantially parallel to said inner wall upon rotation of said shaft, said inner wall substantially completely encircling said surface; said impeller defining with said rear wall a peripheral cearance surrounding said shaft; and an annular body rigid with said shaft and co- 50 axial therewith in said clearance, said body having a diameter equal to a major portion of that of said chamber and being provided with a plurality of axially staggered members projecting generally radially outwardly into said chamber for shredding solid matter in said clearance.

Cal

OTHER REFERENCES Hoelscher (publication) THN 3808, pages l-7, March 1958, published by Machinefabuk Theodor Hoelscher, 241-A. 

1. A PUMP FOR DISPLACING LIQUIDS, COMPRISING A HOUSING FORMING A GENERALLY CIRCULARLY CYLINDRICAL PUMP CHAMBER PROVIDED WITH A SUBSTANTIALLY AXIAL INLET AND A SUBSTANTIALLY RADIAL OUTLET FOR A LIQUID TO BE PUMPED AS WELL AS A REAR WALL TRANSVERSE TO THE AXIS OF SAID CHAMBER; A DRIVE SHAFT EXTENDING AXIALLY INTO SAID HOUSING REMOTE FROM SAID INLET THROUGH SAID REAR WALL AND ROTATABLY JOURNALED IN SAID HOUSING; A GENERALLY ELLIPTICAL FLAT IMPELLER DISK SECURED TO SAID SHAFT WITHIN SAID CHAMBER AND INCLINED TO THE AXIS THEREOF WHILE BEING SPACED FROM AN INNER CYLINDRICAL WALL OF SAID CHAMBER, WHEREBY THE PERIPHERY OF SAID DISK GENERATES A GENERALLY CIRCULARLY CYLINDRICAL SURFACE SUBSTANTIALLY PARALLEL TO SAID INNER WALL UPON ROTATION OF SAID SHAFT, SAID INNER WALL SUBSTANTIALLY COMPLETELY ENCIRCLING SAID SHAFT, SAID IMPELLER DEFINING WITH SAID REAR WALL A PERIPHERAL CLEARANCE SURROUNDING SAID SHAFT; AND AN ANNULAR BODY COAXIAL WITH SAID SHAFT WITHIN SAID CLEARANCE, SAID BODY BEING PROVIDED WITH A PLURALITY OF AXIALLY STAGGERED MEMBERS SPACED FROM SAID DISK AND PROJECTING GENERALLY RADIALLY INTO SAID CHAMBER AND CO-OPERATING WITH SAID DISK FOR SHREDDING SOLID MATTER SUSPENDED IN SAID LIQUID WITHIN SAID CLEARANCE. 